The present invention relates to welding torches and more particularly gas shielded tungsten-arc welding torches, commonly referred to in the trade as TIG torches. The designation TIG refers to tungsten inert gas. TIG welding is an arc welding process originally developed to weld corrosion resistant and difficult to weld metals, such as aluminum and magnesium. The necessary heat for gas tungsten-arc welding is produced by a highly concentrated arc maintained between a non-consumable tungsten electrode and the workpiece to be welded which permits pinpoint control of the heat resulting in a narrow heat affected zone. This is obviously advantageous when welding metals that possess high heat conductivity, such as aluminum and copper. The heat weld zone, the molten metal and the tungsten electrode are shielded from the atmosphere by a blanket of inert gas such as argon or helium which is fed through the electrode holder. This inert shielding gas surrounding the heat weld zone serves to blanket the weld and exclude the active properties in the surrounding air thereby preventing oxidation of the electrode, the weld puddle and the heated weld zone.
While TIG torches are highly versatile in that they are capable of welding all types of metals, their rigid configurations have made their use quite difficult in many work areas of limited or difficult access. As a result, different torches have been provided with different head configurations for use in such areas. For example, one torch with a given head configuration may emit the arc at an angle of about 70 degrees with respect to the handle, another at 90 degrees with respect to the handle, and yet another torch would emit an arc in axial alignment with the torch handle. To utilize this form of flexibility, however, it is necessary to maintain several different torches of varying head configurations which, of course, is very expensive. An attempted solution to this problem is found in U.S. Pat. No. 2,949,526, wherein a body portion of the torch was made removable from the torch handle. However, this approach did little to remedy the situation as the removable body not only comprised the head portion of the torch, but most of the remaining elements as well. Consequently, to maintain an inventory of TIG torch body portions with different head configurations is almost as costly as maintaining an inventory of torches.
Another problem resulting from the rigid construction of TIG torches is the high cost of torch head replacement. The head portion of the torch is susceptible to damage due to its proximity to the heat generated by the arc. While being highly susceptible to damage, the head portion of the torch is nevertheless relatively inexpensive as compared to the torch body. However, due to the rigid unitary construction of the torch, if the torch head becomes damaged and is not removable from the torch body, the entire body must be replaced with the head. In the welding torch of the present invention, the inexpensive head portion of the torch is readily removable from the torch body and is easily replaceable, thereby not only increasing the flexibility of the torch in that the torch can be easily provided with different head portions of varying configurations, but decreasing the cost of part replacement as well.